examples: bistromathic: strengthen tests

* examples/c/bistromathic/bistromathic.test: here.
* examples/test: Be clearer on failing tests.

examples/c/bistromathic/bistromathic.test

@@ -45,9 +45,20 @@ run 0 '0.16
 cat >input <<EOF
 *
 EOF
-run 0 "err: 1.1: syntax error: expected end of file or - or ( or end of line or double precision number or function or variable before *"
+run 0 'err: 1.1: syntax error: expected end of file or - or ( or end of line or double precision number or function or variable before *'
 
 cat >input <<EOF
 1 + 2 * * 3
 EOF
-run 0 "err: 1.9: syntax error: expected - or ( or double precision number or function or variable before *"
+run 0 'err: 1.9: syntax error: expected - or ( or double precision number or function or variable before *'
+
+cat >input <<EOF
+100%
+EOF
+run 0 '100
+err: 1.4: error: invalid character'
+
+cat >input <<EOF
+1 / 0
+EOF
+run 0 'err: 1.1-5: error: division by zero'

examples/c/bistromathic/parse.y

@@ -123,7 +123,7 @@ exp:
   {
     if ($r == 0)
       {
-        yyerror (&@$, "division by zero");
+        yyerror (&@$, "error: division by zero");
         YYERROR;
       }
     else

examples/c/bistromathic/scan.l

@@ -62,6 +62,6 @@
 
 <<EOF>>  return TOK_EOF;
 
-.        yyerror (yylloc, "syntax error, invalid character");
+.        yyerror (yylloc, "error: invalid character");
 %%
 /* Epilogue (C code). */

examples/test

@@ -90,9 +90,12 @@ run ()
       echo "$me: PASS: $number"
     else
       echo "$me: FAIL: $number"
-      echo "$me: expected output:  $out_exp"
+      echo "$me: input:"
-      echo "$me: effective output: $out_eff"
+      sed -e 's/^/  /' input
-      cat err_eff
+      echo "$me: expected output:"
+      echo "$out_exp" | sed -e 's/^/  /'
+      echo "$me: effective output:"
+      echo "$out_eff" | sed -e 's/^/  /'
       exit=false
     fi
   else